1) Field of the Invention
The present invention relates to an occupant-protecting means, such as a seat belt system, for a motor vehicle, especially to a magnet-inclusive component useful in a buckle, a retractor, an acceleration sensor or the like of a seat belt system.
2) Description of the Related Art
A motor vehicle is provided with various safety devices or systems for protecting an occupant in safe in the event of a vehicular emergency such as a collision, led by a seat belt system which restrains and protects the occupant by a webbing. These devices or systems include those using a magnet-inclusive component which makes use of the action of magnetic force.
Illustrative of such devices or systems include an emergency release buckle (ERB) of a passive seat belt system and a buckle of a manual seat belt system, each of said buckles being capable of confirming by a magnetic sensor whether a tongue connected to a webbing is latched or not; a wound webbing length sensor for a retractor, said sensor being capable of detecting the length of a webbing wound on the retractor; and an acceleration sensor (G-sensor) for sensing an acceleration applied in the event of an emergency such as a collision.
These magnet-inclusive components have heretofore been fabricated by assembling magnets with adjacent parts or members in accordance with adhesion or crimping or by fitting magnets between holding surfaces of adjacent parts or members. A magnet however has strong magnetic force. The magnet is therefore attracted toward another magnetic member, whereby it is difficult to handle the magnet upon assembly.
With the foregoing in view and further, taking into additional consideration the tendency that an adjacent portion may be modified and deformed on standing, it is difficult to firmly fix a magnet on an adjacent portion. For firm fixing of a magnet, it is indeed necessary to enclose the magnet by adhering a cover over the magnet.
As a result, these conventional magnet-inclusive components are accompanied by the problems that they require many assembly steps in spite of poor dimensional accuracy and substantial rattling and they are impaired in appearance. Moreover, the application of a cover or the like renders the magnet become more distant from a means on which magnetic force is supposed to act from the magnet, such as a magnetic sensor, resulting in the problem that the performance itself of the magnet is impaired.